package com.juzipi.demo.singleton.type3;

public class SingletonTest3 {

    public static void main(String[] args) {
        //懒汉式1，线程不安全
        Singleton instance = Singleton.getInstance();
        Singleton instance1 = Singleton.getInstance();
        System.out.println(instance.hashCode());
        System.out.println(instance1.hashCode());
        System.out.println(instance.equals(instance1));
        System.out.println(instance == instance1);

    }
}

class Singleton{
    private static Singleton instance;

    private Singleton(){

    }
    //提供一个静态的公有方法，当使用到该方法时，才去创建 instance
    //即懒汉式

    public static Singleton getInstance(){
        if (instance == null){
            instance = new Singleton();
        }
        return instance;
    }

}
